The irradiation of micrometer-thin metal foils by modern high-energy short-pulse lasers with intensities above 10^18 W/cm2 leads to, amongst other things, the acceleration of ion beams with energies in the range of mega-electron-volts (MeV). Initially, the laser pulse accelerates electrons to relativistic energies, which then propagate through the foil. As soon as the electrons leave the foil’s rear side, an electric field with a field strength of about 10^12 V/m is generated. This effectively accelerates adsorbed protons from the foil surface in direction of the target normal. The quasi-neutral beams generated in such a manner consist of more than 1012 protons in a short, pico-second duration pulse. Possible applications are the diagnostics of dense plasmas, the utilization as compact injectors for particle accelerators, the energy generation by fast ignition in inertial fusion energy, as well as a potential utilization in cancer therapy with ion beams. Laser-accelerated ion beams exhibit some beam properties that are superior to ion beam properties from conventional ion sources. This motivates their application as a next generation ion source. Until today, though, there is no complete model for the laser ion-acceleration that can be used for estimates of all beam parameters. However, the development of applications requires an accurate knowledge of the space and momentum distribution (phase space) of the ions, as well as the best-possible modeling of the acceleration process. Therefore the measurement technique of “Radiochromic film Imaging Spectroscopy (RIS)” has been developed. The dosimetry films needed for RIS have been absolutely calibrated for protons at the tandem accelerator at the Max-Planck-Institut für Kernphysik in Heidelberg, Germany. Furthermore, RIS uses the method of ion beam manipulation by micrometer-sized deformation of the foil surface. The modulations of the foil’s rear side are transferred in the ion beam and are imaged into a stack of radiochromic films. A technique has been developed to insert equidistant, micrometer-sized grooves (distance either 3, 5 or 10 micrometer) on the surface of thin foils with thicknesses from 5 to 50 micrometers. This is done by ultra-high precision-chipping of a carrier material, followed by electro-plated deposition of the foil and subsequent etching of the carrier material. The micro-structured foils have been successfully used in experiments at the Petawatt High Energy Laser for Heavy Ion eXperiments (PHELIX) at the GSI Helmholtzzentrum für Schwerionenforschung GmbH (Darmstadt, Germany in March 2006), in two experimental campaigns at the TRIDENT laser at Los Alamos National Laboratory (New Mexico, USA, May 2005 and April 2006), at the 100 TW laser at the Laboratoire pour l’Utilisation des Lasers Intenses (École Polytechnique, Palaiseau, France, June 2006) and at the Z -Petawatt laser at Sandia National Laboratories (New Mexico, USA, December 2007). The data analysis not only confirms the findings obtained in earlier experiments, but additionally leads to conclusions about the electric fields driving the acceleration. The results obtained with RIS have been considered in the development of the Charged Particle Transfer (CPT) code, that can be used for a three-dimensional simulation of the ion-acceleration from the rear side of the foil. CPT can fully reproduce the measured data. The underlying model in CPT has been confirmed by analytical examinations, computer simulations of a one-dimensional fluid expansion with charge separation and two-dimensional, relativistic Particle-In-Cell (PIC) simulations. In addition, experiments on the action of a shaped laser beam profile at the target front side on the ion acceleration from the foil’s rear side have been performed at the above-mentioned laser systems. It could be shown, that an elliptically shaped laser focus results in an elliptically shaped proton beam. Moreover, the laser beam profile impression becomes weaker with increasing target foil thickness. The simultaneous measurement of the proton beam source size by the use of the micro-structured foils lead to the conclusion that the electron transport in50 micrometer thick foils is basically determined by small-angle scattering but is negligible for 13 micrometer thin foils. For the interpretation and reproduction of the experimental results the Sheath-Accelerated Beam Ray-tracing for IoN Analysis code (SABRINA) has been developed. This code calculates the intensity profile of the proton beam for a given laser beam profile, under consideration of small-angle scattering. The observed, unexpectedly large emission zone at thin foils is most likely the result of re-circulating electrons in the target foil. Experiments with different target geometries have been performed for a further optimization of laser-accelerated proton beams. The RIS-data analysis from experiments with novel, cone-shaped targets with a flat rear side at TRIDENT with moderate intensities of 1019 W/cm2 with 20 J in 600 fs showed a nearly two-fold increase of the maximum energy of the accelerated proton beams, a four-fold better conversion efficiency of laser energy to ion beam energy as well as a 13-fold higher ion number above 10 MeV compared to data from flat foils. The interpretation of measurements of the energy-dependent source size and divergence and PIC simulations evidence a bell-shaped electron sheath at the foil’s rear side as the originator of the divergence of laser-accelerated ion beams. The divergence could be compensated by geometrical deformation of the target foil. First experiments on the collimation of laser-accelerated proton beams have been obtained at Z -Petawatt. The injection of laser-accelerated ion beams in conventional accelerator structures requires a separation of the co-propagating electrons and protons. This can happen by a dipole magnet, as could be shown in experiments at Z -Petawatt. During the same experimental campaign the first controlled transport and focusing of laser-accelerated MeV-protons could be demonstrated. For that purpose miniature quadrupole-lenses, based on permanent magnets with field gradients up to 500 T/m have been utilized. 106 protons with an energy of 14 MeV could be reproducibly focused to a beam spot of about 300 x